Field of the Invention
This document relates to a touch sensor integrated type display device which is capable of recognizing a user's touch.
Discussion of the Related Art
Recently, various input devices such as a keyboard, a mouse, a trackball, a joystick, and a digitizer have been used to configure an interface between users and home appliances or various kinds of information communication equipment. However, such input devices as a keyboard, a mouse, etc require the user to learn to use them and take up space. Therefore, the demand for input devices that are convenient and easy to use and reduce erroneous operations is growing more and more. In response to this demand, a touch sensor for enabling a user to input information by directly touching the screen with their hand or a pen was suggested.
The touch sensor is simple to use, has less malfunctions, and enables the user to input without using an additional input device. In addition, the touch sensor can be applied to various display devices because it enables the user to operate it quickly and easily through content displayed on the screen.
Touch sensors can be classified into add-on type and on-cell type. In the add-on type, a display device and a touch panel having a touch sensor are separately manufactured, and the touch panel is attached onto an upper substrate of the display device. In the on-cell type, a touch sensor is directly formed on the surface of an upper glass substrate of a display device.
However, the add-on type sensor has a structure in which the completed touch panel is mounted on the display device and has various problems, such as increased thickness or reduced visibility due to low brightness of the display device.
In addition, the on-cell type touch sensor has a structure in which a touch panel is formed on the upper surface of the display device and can have a reduced thickness compared to the add-on type but still has the problem of the increase in entire thickness due to a driving electrode layer, a sensing electrode layer, and an insulation layer for insulating the driving electrode layer and the sensing electrode layer, which constitute the touch sensor. As such, the number of processes and the manufacturing cost in the on-cell type touch sensor increase.
Accordingly, the need for a display device capable of solving the related art problems has arisen.
Hereinafter, a related art touch sensor integrated type display device will be described with reference to FIGS. 1A and 1B. FIG. 1A is a top plan view of a related art touch sensor integrated type display device. FIG. 1B is a cross-sectional view taken along the line I-I′ of FIG. 1A.
With reference to FIGS. 1A and 1B, a touch sensor integrated type display device comprises an active area AA where touch electrodes are formed and data is displayed and a bezel area AA which is located outside the active area AA and where wires connecting touch electrodes to constitute touch electrode lines are formed.
The active area AA comprises a plurality of first touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34, and Tx41 to Tx44 divided in a first direction (e.g., along the x axis) and a second direction (e.g., along the y axis) which cross each other, a plurality of first sub routing wires TW11 to TW14, TW21 to TW24, TW31 to TW34, and TW41 to TW44 connected to the plurality of first touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34, and Tx41 to Tx44, respectively, and extending in the second direction, and a plurality of second touch electrodes Rx1 to Rx3 located between first touch electrodes neighboring in the first direction and arranged in the second direction.
The plurality of first touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34, and Tx41 to Tx44 are connected to each other by the first sub routing wires TW11 to TW14, TW21 to TW24, TW31 to TW34, and TW41 to TW44 respectively connected to the first touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34, and Tx41 to Tx44, first connecting wires TW1c to TW4c, and first main routing wires TW1 to TW4 to constitute a plurality of first touch electrode lines Tx1 to Tx4 arranged in the first direction.
Specifically, the first row of 1-1 touch electrodes Tx11 to Tx14 arranged in the first direction (along the x axis) are connected to each other by the 1-1 sub routing wires TW11 to TW14 respectively connected to the 1-1 touch electrodes Tx11 to Tx14, the 1-1 connecting wire TW1c connecting the 1-1 sub routing wires TW11 to TW14, and the 1-1 main routing wire TW1 connected to the 1-1 connecting wire TW1c to constitute a 1-1 touch electrode line Tx1 for the first row.
The second row of 1-2 touch electrodes Tx21 to Tx24 arranged in the first direction (along the x axis) are connected to each other by the 1-2 sub routing wires TW21 to TW24 respectively connected to the 1-2 touch electrodes Tx21 to Tx24, the 1-2 connecting wire TW2c connecting the 1-2 sub routing wires TW21 to TW24, and the 1-2 main routing wire TW2 connected to the 1-2 connecting wire TW2c to constitute a 1-2 touch electrode line Tx2 for the second row.
The third row of 1-3 touch electrodes Tx31 to Tx34 arranged in the first direction (along the x axis) are connected to each other by the 1-3 sub routing wires TW31 to TW34 respectively connected to the 1-3 touch electrodes Tx31 to Tx34, the 1-3 connecting wire TW3c connecting the 1-3 sub routing wires TW31 to TW34, and the 1-3 main routing wire TW3 connected to the 1-3 connecting wire TW3c to constitute a 1-3 touch electrode line Tx3 for the third row.
The fourth row of 1-4 touch electrodes Tx41 to Tx44 arranged in the first direction (along the x axis) are connected to each other by the 1-4 sub routing wires TW41 to TW44 respectively connected to the 1-4 touch electrodes Tx41 to Tx44, the 1-4 connecting wire TW4c connecting the 1-4 sub routing wires TW41 to TW44, and the 1-4 main routing wire TW4 connected to the 1-4 connecting wire TW4c to constitute a 1-4 touch electrode line Tx4 for the fourth row.
The 2-1 touch electrode Rx1 is located between the first touch electrodes Tx11, Tx21, Tx31, and Tx41 in the first column and the first touch electrodes Tx12, Tx22, Tx32, and Tx42 in the second column, which neighbor in the first direction, to constitute a 2-1 touch electrode line Rx1 for the first column.
The 2-2 touch electrode Rx2 is located between the first touch electrodes Tx12, Tx22, Tx32, and Tx42 in the second column and the first touch electrodes Tx13, Tx23, Tx33, and Tx43 in the third column, which neighbor in the first direction, to constitute a 2-2 touch electrode line Rx2 for the second column.
The 2-3 touch electrode Rx3 is located between the first touch electrodes Tx13, Tx23, Tx33, and Tx43 in the third column and the first touch electrodes Tx14, Tx24, Tx34, and Tx44 in the fourth column, which neighbor in the first direction, to constitute a 2-3 touch electrode line Rx3 for the third column.
The bezel area BA is located outside the active area AA, and comprises various wires and pads. The wires comprise touch wires TW11 to TW14, TW21 to TW24, TW31 to TW34, TW41 to TW44, TW1c to TW4c, TW1 to TW4; and RW1 to RW3 connected to the first and second touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34, Tx41 to Tx44; and Rx1 to Rx3, gate wires (not shown) connected to a gate driving circuit, and data wires (not shown) connected to a data driving circuit. The pads comprise touch pads TP1 to TP4 and RP1 to RP3 connected to the touch wires.
The first and second touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34, Tx41 to Tx44, and Rx1 to Rx3 within the active area AA are divided from the common electrodes of the display device. They operate as common electrodes during a display driving operation for displaying data and as touch electrodes during a touch driving operation for recognizing a touch position.
The above-described touch sensor integrated type display device has the advantage of reducing the number of processes for forming a touch sensor element and making thin products because common electrodes also function as touch driving electrodes or touch sensing electrodes of a touch sensor. Also, it has the advantage of not needing to increase the left and right sides of the bezel area BA because the first sub routing wires TW11 to TW14, TW21 to TW24, TW31 to TW34, and TW41 to TW44 for connecting the first touch electrodes Tx11 to Tx14, Tx21 to Tx24, Tx31 to Tx34, and Tx41 to Tx44 extend to the bottom side of the bezel area BA in parallel with the second touch electrodes Rx1 to Rx3 and the four to first touch electrode lines Tx1 to Tx4 are formed by the first connecting wires TW1c to TW4c formed on the bottom side of the bezel area BA.
In the above-described related art touch sensor integrated type display device, all of the first touch electrodes are the same size. The second touch electrodes Rx1 and Rx2 in the first and second columns are positioned on either side of the first touch electrodes Tx12, Tx22, Tx32, and Tx42 in the second column in the middle of the active area AA, and the second touch electrodes Rx2 and Rx3 in the second and third columns are positioned on either side of the first touch electrodes Tx13, Tx23, Tx33, and Tx43 in the third column in the middle of the active area AA. On the other hand, the second touch electrode Rx1 in the first column is positioned on only one side of the first touch electrodes Tx11, Tx21, Tx31, and Tx41 in the first column situated at either end, i.e., left end, of the active area AA, and the second touch electrode Rx3 in the third column is positioned only one side of the first touch electrodes Tx14, Tx24, Tx34, and Tx44 in the fourth column situated at either end, i.e., right end, of the active area AA. Accordingly, the left and right halves of the first touch electrodes Tx12, Tx22, Tx32, and Tx42 in the second column with two second touch electrodes on either side are respectively sensed by the second touch electrodes Rx1 and Rx2 in the first and second columns, and the left and right halves of the first touch electrodes Tx13, Tx23, Tx33, and Tx43 in the third column with two second touch electrodes on either side are respectively sensed by the second touch electrodes Rx2 and Rx3 in the second and third columns; whereas the entire area of the first touch electrodes Tx11, Tx21, Tx31, and Tx41 in the first column with only one second touch electrode on either side and situated at either end of the active area AA is sensed by the second touch electrode Rx1 in the first column and the entire area of the first touch electrodes Tx14, Tx24, Tx34, and Tx44 in the fourth column with only one second touch electrode on either side and situated at either end of the active area AA is sensed by the second touch electrode Rx in the third column. Accordingly, the region of the first touch electrodes sensed by the second touch electrodes is different on the edges and middle of the active area, thereby causing touch accuracy deterioration.